An Argentine judge has overturned presidential pardons granted to two top ministers from the 1976 to 1983 military dictatorship.

The judge Monday ruled as unconstitutional the pardons granted by President Carlos Menem in 1989 and 1990 to Jose Alfredo Martinez de Hoz, a former economy minister, and former Interior Minister Albano Harguindeguy.

The two ministers were investigated for their alleged role in the abductions of textile businessman Federico Gutheim and his son, Miguel, in the late 1970s. Authorities say the motive was to pressure the Gutheims into accepting an export contract that would have benefited the Economy Ministry.

Officials say that under Argentina's military dictatorship, about 13,000 people died or disappeared during the crackdown on dissidents or political enemies. Human rights groups estimate nearly 30,000 people were killed.